try to implement same boundary conditions in mpi
Merge branch 'develop' into mpi
Trying to debug new mpi functions
Still trying to debug mpi_derivatives for various BC
some clean up
reviewed creation of derivatives
added laplace_t.cu
added another laplace
added another laplace
fixed merge conflict
added benchmark file
renamed w2d functions as weights, deleted some deprecated files, merged lalace and polarisation into elliptic class, merged Helmholtz and Maxwell in Helmholtz
adapted feltor to new class Elliptic, made feltor.cu and feltor_hpc.cu construct cylindrical grids
adapted feltorEM to new interface
fixed merge conflicts from cylindrical branch
fixed merge conflict in feltor.cu